Electrical connection



Nov. 5, 1929. c. F. GOUDY 1,734,432

ELECTRICAL CONNECTION Filed June 22. 1926 INVENTOR Gags/5.5M M AMW Patented Nov. 5, 1929 UNITED STATES PATENT OFFICE CARL I. GOUDY, Ol' FINISHING, NEW YORK, ASSIGNOR TO PACENT ELECTRIC COMPANY, INC., 0] NEW YORK, N. Y., A CORPORATION OF NEW YORK ELECTRICAL CONNECTION Application filed June 22,

This invention relates to the use of power amplifiers with radio receiving sets.

These amplifiers usually involve a stage of audio-frequency amplification. Because of certain faults in the average audio-frequency transformer, it is unwise to use more than two stages of audio-frequency amplification. The average type of radio receiving set has two audio-frequency stages. To add to those two stages, a third stage of audio-frequency, with the ordinar transformers, would introduce objectionab e distortion and therefore it is inadvisable to connect a power amplifier with the second audio stage of the usual receiving set.

Where receiving sets are equipped with output jacks in the detector and first audio stages, the power amplifier can be easily connected in by simply plugging in on one of these jacks. In the average receiving set, however, there are no jacks for the detector and first audio stages so that if a power amplifier is plugged in, it has to be connected in on the second audio stage and becomes objectionable because of the distortion which results.

The objects of the invention are to enable the connection of the power amplifier with the detector or first audio stage, in cases where no jacks are provided at these points and to provide connecting means for the purpose which will be simple, inexpensive and easily installed in any usual or ordinary receiving set.

In the attainment of these objects a novel form of connection is used, involving a coupling which is slipped over the output prong of the detector or first audio tube, which coupling makes connection with said output prong and at the same time insulates said prong from the cooperating contact in the socket so that a wire led oif from said coupling serves to by-pass the output from this tube direct to the input of the power amplifier.

The invention involves further novel features of construction, combinations and relations of parts as hereinafter set forth and covered broadly in the appended claims.

In the drawing accompanying and forming 1926. Serial No. 117,655.

part of this specification one of the practical embodiments of the invention and one mode of use are illustrated, but it should be understood that the structure and the method of use may be varied without departure from the broad spirit and scope of the invention.

Figure 1 is a schematic illustration of an ordinary five tube radio receiving set illustrating use of the invention for coupling a power amplifier to the first audio stage.

F1gure 2 is an enlarged broken sectional view of the connector as applied to the tube.

Ftigure 3 is a bottom plan view of these par s.

Figure 4 is a further enlarged broken sectional view of the entire connector.

The radio receiving set indicated generally at 5 is of typical design having two radio frequency tubes 6, 7, a detector tube 8 and first and second audio stage tubes 9, 10.

The power amplifier is indicated generally at 11 and may be considered as having a rectifying tube 12 and an audio amplifying tube 13. This amplifier is shown as supplied with house lighting current by means of a cord circuit 14.

The input side of the amplifier is shown as connected with the receiving set by means of an extension cord 15 and the output side of the amplifier is shown connected by another cord circuit 16 with the speaker 17.

One terminal of the cord connection between the receiving set and amplifier is shown connected at 18 with one side of the telephone plug 19, which is entered in the usual way in the output jack 20 of the receiving set. The other terminal 21 of this same cord circuit is shown held by a binding screw 22 in the socket 23 in a terminal member 24 which is attached to one end of a flexible wire 25. The opposite end of this wire is equipped with a coupling device for connecting the wire with the output prong of the tube and for insulating said prong from the regular output socket contact.

This special coupling is illustrated as a small thimble 26 of insulating material of a size to fit snugly over the plate prong 27 of the tube and carrying at its upper end, a spring ring 28 to which the wire end is attached at 29 and which has at one end an inwardly projecting point 30 to make contact with the tube prong. This spring terminal ring is shown as held by its own resiliency in a groove 31 formed exteriorly in an annular enlargement or head 32 at the upper end of the thimble and the tip of the ring is shown as located in an opening 33 extending radially inwardly from the annular holding groove 31.

The terminal ring 28 may be made of piano wire or other suitable spring material. At the point where the wire is soldered or otherwise secured thereto, the ring may be given an outward bend, as illustrated particularly at 34 in Figure 3. After securing the wire at this point, the parts can be assembled by simply snapping the ring over the head of the insulating thimble in position where the terminal point of the ring will enter theradial opening 33, whereupon the ring will automatically snap into position in its seat on the thimble.

In using the device, it is customary to first apply the insulating coupling to the plate or output prong of the tube and then to drop the other end of the wire connection down through the tube holding socket 35, after which the tube may be entered in its socket in the usual way and the terminal 24 of the wire connection be engaged with the loose terminal 21 of the telephone cord. When passing the connection through the socket, the usual precautions should be observed as to shutting oil the current supply so as to prevent any accidental short circuits. If it is found that the wrong plug terminal is connected with the telephone cord, this can quickly be correctedby changing the cord terminal 18 over to the other socket in the plug, the point being that this cord terminal should be connected usually with the positive side of the high voltage or B-battery current source.

The invention, it will be seen, is readily applied to any ordinary receiving set and provides simple means by which the last audio stage may be cut out of circuit and the output of the first audio stage be relayed to the power amplifier. This connection also is such as tobe usable with the average tube socket and is of such a nature as to readily fit in with the ordinary receiving set. Thus in Figure 1 it will be understood that the bypass connection 25 may be brought out beneath or over the top or out at the back of the front panel of the set. The thickness of insulation at the end of the thimble is left suflicient to prevent any current flow to the contact spring 36 with which the plate prong usually contacts, but is insuflicient to destroy or permanently bend this spring. The thimble is quickly applied or disconnected and the spring tension of the terminal ring provides a scraping contact with the prong and also assists in holding the thimble yieldingly in place on the prong. If the power amplifier provides suflicient power of itself, then the first audio stage may be eliminated by engaging the by-pass connection directly with the output prong of the detector tube. Other uses may occur to those familiar with the subject.

\Vhat is claimed is:

1. A connection for by-passing the second audio-frequency stage of a radio receiving set comprising a thimble applicable to the output terminal prong of the first audio-frequency tube of the set, said thimble having a contact element in engagement with the prong and an insulating portion overstanding the end of the prong, an extension wire connected with said contact and a terminal on said wire for connection with the terminal of a telephone cord or the like.

2. A by-passing connection for radio receiving sets comprising. an insulating thimble engageable over a prong of a tube and providing thereby an insulating cap preventing contact between said prong and the normally cooperating socketcontact, an extension wire attached to said thimble and having a terminal projecting within the thimble for engagement with the prong over which the thimble is slipped.

3. A by-passing connection for radio receiving sets comprising an insulating thimble engageable over a prong of a tube and providing thereby an insulating cap preventing contact between said prong and the normally cooperating socket contact, an extension wire attached to said thimble and having a terminal projecting within the thimble for engagement with the prong over which the thimble is slipped and a cord tip receiving terminal on the free end of said extension wire.

4. A by-passing connection for radio receiving sets comprising an insulating thimble engageable over a single terminal prong of a tube, a spring ring seated on said thimble and having an inwardly directed terminal point projecting into the insulating thimble and an extension wire connected with said spring ring.

,5. A by-passing connection for radio receiving sets comprising an insulating thimble for engagement over a terminal prong of a tube, a spring ring seated on said thimble and having an inwardly-directed terminal point projecting into the thimble and an extension wire connected with said spring ring, the thimble having an external annular groove receiving the ring and a radial opening extended inwardly from said groove for receiving the terminal point of the ring.

6. An 7 attachment of the character disclosed, comprising an insulating thimble engngeable over the terminal prong of a socalled vacuum tube, a spring contact carried by said thimble for engagement with the prong to which the thimble is ap lied and a flexible conductor connected with said contact and having means at its free end for connection with a telephone cord tip or the like.

7. As a new article of manufacture, a bypassing connector for radio tubes and sockets, comprising a sleeve member engageable over one prong of a radio tube and having an insulating portion to prevent contact etween that prong and the socket terminal with which said prong would ordinarily cooperate and a metallic terminal element on said sleevelike member, said terminal element being relatively positioned to make contact with the prong on which the sleeve-like member is engaged and adapted to have an external conductor connected therewith to provide a by-pass from the normal circuit of said pron and its normal cooperating socket termina In witness whereof, I have hereunto set my hand this 18th day of June, 1926.

CARL F. GOUDY. 

